Two days after a spinal anesthesia for knee surgery, a patient reports a severe unilateral headache not posture-related. The LEAST likely cause is which?

Two days after a spinal anesthesia for knee surgery, a patient reports a severe unilateral headache not posture-related. The LEAST likely cause is which?

• A. Caffeine withdrawal
• B. Malingering
• C. Viral illness
• D. Postdural puncture headache

Answer: (D)

The main idea here is how post-dural puncture headache (PDPH) presents compared with other headaches after neuraxial anesthesia. PDPH is classically orthostatic: it starts after dural puncture, is usually most severe when the patient sits or stands, and improves when lying down. It typically appears within the first day or two after the procedure. If the patient’s severe headache is unilateral and not related to posture, PDPH becomes unlikely, because the hallmark feature would be the postural component. The question asks for the least likely cause given a non–posture-related headache after spinal anesthesia, so PDPH fits poorly with the presentation and is the best choice for the least likely. Caffeine withdrawal can cause headaches after stopping caffeine, often presenting as a daily-throbbing headache that can be unilateral or diffuse and is not tied to posture. Viral illnesses can trigger migraines or other unilateral headaches, which likewise aren’t posture-dependent. Malingering is possible in theory, but the lack of a posture relationship makes it less grounded in a physiological mechanism here.

The main idea here is how post-dural puncture headache (PDPH) presents compared with other headaches after neuraxial anesthesia. PDPH is classically orthostatic: it starts after dural puncture, is usually most severe when the patient sits or stands, and improves when lying down. It typically appears within the first day or two after the procedure.

If the patient’s severe headache is unilateral and not related to posture, PDPH becomes unlikely, because the hallmark feature would be the postural component. The question asks for the least likely cause given a non–posture-related headache after spinal anesthesia, so PDPH fits poorly with the presentation and is the best choice for the least likely.

Caffeine withdrawal can cause headaches after stopping caffeine, often presenting as a daily-throbbing headache that can be unilateral or diffuse and is not tied to posture. Viral illnesses can trigger migraines or other unilateral headaches, which likewise aren’t posture-dependent. Malingering is possible in theory, but the lack of a posture relationship makes it less grounded in a physiological mechanism here.